Initial thoughts: half the length and weight of the f2.8 version, just what a landscape photographer like me needs. Will I miss the 1.4 times converter? Yes, but not for landscapes, 300 mm full-frame equivalent is quite long enough. In use, it feels much the same size as my 12-40 and the 7-14 f/2.8 lenses - I no longer feel I'm carrying around a monster, or worse, leaving it at home because it's just too big.